[PATCH] simulate-thread tweaks and fixes
I've been toying with the simulate-thread framework a bit. With the
timeout threshold is back to where it originally was, the spectre of
huge log files when an infinite loop happens is back.
This patch has the following modifications:
1) An instruction count threshold has been added.
This will truly prevent infinite loops which were the original
issue. If the count reaches the threshold value, the test case fails.
I've set the current limit to 10,000, which I would expect to be
sufficient. The highest Ive seen so far is 877, but I'm sure someone
will find something higher :-). A testcase can override this value if
it wishes. If we encounter targets where this is not high enough, we
can raise it further. The main point is to avoid generating 10's of
gigabytes of log files when a fast machine hits an infinite loop and the
time based timeout doesnt kick in quickly enough.
If a test does fail for this reason, the log file will issue a FAIL
message indicating the instruction count threshold was exceeded.
2) I tweaked the atomic-load-int128.c testcase to avoid an inadvertent
hostile thread situation that was not intended.
3) The speculative-store.c testcase had a bug in it where the verify
function was not returning a value when successful. ThIs resulted in an
UNSUPPORTED result occasionally because the testcase didn't run far
enough to indicate GDB had successfully run, yet no FAIL was issued.
4) I lowered the hostile thread threshold by an order of magnitude so
that if a hostile thread is encountered frequently, it wont rapidly
approach the new instruction count threshold. This could happen on
compare_and_swap loop targets.
I've tried this on x86_64-unknown-linux-gnu and everything seems good.
If anyone wants to try it on their more stressed arch, all you need to
do is apply the patch to the testsuite and run 'make check-gcc
RUNTESTFLAGS=simulate-thread.exp' to see if the results are as expected.
OK for mainline?
Andrew
* gcc.dg/simulate-thread/simulate-thread.gdb: Use return value from
simulate_thread_wrapper_other_threads
* gcc.dg/simulate-thread/atomic-load-int128.c (simulate_thread_main):
Move initialization of 'value' to main().
(main): Initialize 'value';
* gcc.dg/simulate-thread/speculative-store.c
(simulate_thread_step_verify): Return 0 when successful.
* gcc.dg/simulate-thread/simulate-thread.h (HOSTILE_THREAD_THRESHOLD):
Reduce threshold.
(INSN_COUNT_THRESHOLD): New. Instruction limit to terminate test.
(simulate_thread_wrapper_other_threads): Return a success/fail value
and issue an error if the instruction count threshold is exceeded.
Index: testsuite/gcc.dg/simulate-thread/simulate-thread.gdb
===
*** testsuite/gcc.dg/simulate-thread/simulate-thread.gdb (revision 184447)
--- testsuite/gcc.dg/simulate-thread/simulate-thread.gdb (working copy)
*** run
*** 5,11
set $ret = 0
while (simulate_thread_fini != 1) (! $ret)
! call simulate_thread_wrapper_other_threads()
stepi
set $ret |= simulate_thread_step_verify()
end
--- 5,11
set $ret = 0
while (simulate_thread_fini != 1) (! $ret)
! set $ret |= simulate_thread_wrapper_other_threads()
stepi
set $ret |= simulate_thread_step_verify()
end
Index: testsuite/gcc.dg/simulate-thread/atomic-load-int128.c
===
*** testsuite/gcc.dg/simulate-thread/atomic-load-int128.c (revision 184447)
--- testsuite/gcc.dg/simulate-thread/atomic-load-int128.c (working copy)
*** void simulate_thread_main()
*** 105,113
{
int x;
- /* Make sure value starts with an atomic value now. */
- __atomic_store_n (value, ret, __ATOMIC_SEQ_CST);
-
/* Execute loads with value changing at various cyclic values. */
for (table_cycle_size = 16; table_cycle_size 4 ; table_cycle_size--)
{
--- 105,110
*** void simulate_thread_main()
*** 126,131
--- 123,132
main()
{
fill_table ();
+
+ /* Make sure value starts with an atomic value from the table. */
+ __atomic_store_n (value, table[0], __ATOMIC_SEQ_CST);
+
simulate_thread_main ();
simulate_thread_done ();
return 0;
Index: testsuite/gcc.dg/simulate-thread/speculative-store.c
===
*** testsuite/gcc.dg/simulate-thread/speculative-store.c (revision 184447)
--- testsuite/gcc.dg/simulate-thread/speculative-store.c (working copy)
*** int simulate_thread_step_verify()
*** 24,29
--- 24,30
printf(FAIL: global variable was assigned to. \n);
return 1;
}
+ return 0;
}
int simulate_thread_final_verify()
Index: testsuite/gcc.dg/simulate-thread/simulate-thread.h
===
*** testsuite/gcc.dg/simulate-thread/simulate-thread.h (revision
Re: [PATCH] simulate-thread tweaks and fixes
On Fri, Feb 24, 2012 at 12:38:56PM -0500, Andrew MacLeod wrote: I've been toying with the simulate-thread framework a bit. With the timeout threshold is back to where it originally was, the spectre of huge log files when an infinite loop happens is back. This patch has the following modifications: 1) An instruction count threshold has been added. This will truly prevent infinite loops which were the original issue. If the count reaches the threshold value, the test case fails. I've set the current limit to 10,000, which I would expect to be sufficient. The highest Ive seen so far is 877, but I'm sure someone will find something higher :-). A testcase can override this value if it wishes. If we encounter targets where this is not high enough, we can raise it further. The main point is to avoid generating 10's of gigabytes of log files when a fast machine hits an infinite loop and the time based timeout doesnt kick in quickly enough. If a test does fail for this reason, the log file will issue a FAIL message indicating the instruction count threshold was exceeded. 2) I tweaked the atomic-load-int128.c testcase to avoid an inadvertent hostile thread situation that was not intended. 3) The speculative-store.c testcase had a bug in it where the verify function was not returning a value when successful. ThIs resulted in an UNSUPPORTED result occasionally because the testcase didn't run far enough to indicate GDB had successfully run, yet no FAIL was issued. 4) I lowered the hostile thread threshold by an order of magnitude so that if a hostile thread is encountered frequently, it wont rapidly approach the new instruction count threshold. This could happen on compare_and_swap loop targets. I've tried this on x86_64-unknown-linux-gnu and everything seems good. If anyone wants to try it on their more stressed arch, all you need to do is apply the patch to the testsuite and run 'make check-gcc RUNTESTFLAGS=simulate-thread.exp' to see if the results are as expected. Andrew, Works fine on x86_64 darwin when applied to curren gcc trunk... Native configuration is x86_64-apple-darwin11.3.0 === gcc tests === Schedule of variations: unix/-m32 unix/-m64 Running target unix/-m32 Using /sw/share/dejagnu/baseboards/unix.exp as board description file for target. Using /sw/share/dejagnu/config/unix.exp as generic interface file for target. Using /sw/src/fink.build/gcc47-4.7.0-1/gcc-4.7-20120224/gcc/testsuite/config/default.exp as tool-and-target-specific interface file. Running /sw/src/fink.build/gcc47-4.7.0-1/gcc-4.7-20120224/gcc/testsuite/gcc.dg/simulate-thread/simulate-thread.exp ... === gcc Summary for unix/-m32 === # of expected passes76 # of unsupported tests 8 Running target unix/-m64 Using /sw/share/dejagnu/baseboards/unix.exp as board description file for target. Using /sw/share/dejagnu/config/unix.exp as generic interface file for target. Using /sw/src/fink.build/gcc47-4.7.0-1/gcc-4.7-20120224/gcc/testsuite/config/default.exp as tool-and-target-specific interface file. Running /sw/src/fink.build/gcc47-4.7.0-1/gcc-4.7-20120224/gcc/testsuite/gcc.dg/simulate-thread/simulate-thread.exp ... === gcc Summary for unix/-m64 === # of expected passes88 # of unsupported tests 2 === gcc Summary === # of expected passes164 # of unsupported tests 10 /sw/src/fink.build/gcc47-4.7.0-1/darwin_objdir/gcc/xgcc version 4.7.0 20120224 (experimental) (GCC OK for mainline? Andrew * gcc.dg/simulate-thread/simulate-thread.gdb: Use return value from simulate_thread_wrapper_other_threads * gcc.dg/simulate-thread/atomic-load-int128.c (simulate_thread_main): Move initialization of 'value' to main(). (main): Initialize 'value'; * gcc.dg/simulate-thread/speculative-store.c (simulate_thread_step_verify): Return 0 when successful. * gcc.dg/simulate-thread/simulate-thread.h (HOSTILE_THREAD_THRESHOLD): Reduce threshold. (INSN_COUNT_THRESHOLD): New. Instruction limit to terminate test. (simulate_thread_wrapper_other_threads): Return a success/fail value and issue an error if the instruction count threshold is exceeded. Index: testsuite/gcc.dg/simulate-thread/simulate-thread.gdb === *** testsuite/gcc.dg/simulate-thread/simulate-thread.gdb (revision 184447) --- testsuite/gcc.dg/simulate-thread/simulate-thread.gdb (working copy) *** run *** 5,11 set $ret = 0 while (simulate_thread_fini != 1) (! $ret) ! call simulate_thread_wrapper_other_threads() stepi set $ret |= simulate_thread_step_verify() end --- 5,11 set $ret = 0 while (simulate_thread_fini != 1) (! $ret) !
Re: [PATCH] simulate-thread tweaks and fixes
On Feb 24, 2012, at 9:38 AM, Andrew MacLeod wrote: I've been toying with the simulate-thread framework a bit. OK for mainline? Ok. Don't know why you ask... I'd ask you if I wanted to make a change to the file... Anyway, I reviewed it, and didn't spot anything bad.
Re: [PATCH] simulate-thread tweaks and fixes
On 02/24/2012 02:10 PM, Mike Stump wrote: On Feb 24, 2012, at 9:38 AM, Andrew MacLeod wrote: I've been toying with the simulate-thread framework a bit. OK for mainline? Ok. Don't know why you ask... I'd ask you if I wanted to make a change to the file... Anyway, I reviewed it, and didn't spot anything bad. Just dotting my i's :-) I figured I'd give anyone who had issues earlier with these tests a bit of a chance to make sure it works if they wanted :-) Thanks. Andrew
